The summits and dry valleys of the TAM are some of the few places in Antarctica not covered by ice, the highest of which rise more than 4,500 metres (14,800 ft) above sea level. The McMurdo Dry Valleys lie near McMurdo Sound and represent a special Antarctic phenomenon: landscapes that are snow and ice free due to the extremely limited precipitation and ablation of ice in the valleys. The highest mountain of the TAM is 4,528 m high Mount Kirkpatrick in the Queen Alexandra Range. Isolated peaks surrounded by ice are referred to as nunataks.

Much of the range remained unexplored until the late 1940s and 1950s, when missions such as Operation Highjump and the International Geophysical Year made extensive use of aerial photography and concentrated on a thorough investigation of the entire continent. The name "Transantarctic Mountains" were recommended in 1962 by the US-ACAN committee, a US authority for geographic names. This purely descriptive label (in contrast to many other geographic names on Antarctica) is internationally accepted at present.

Ice from the East Antarctic ice sheet flows through the Transantarctic Mountains via a series of outlet glaciers into the Ross Sea, Ross Ice Shelf, and West Antarctic Ice Sheet. These glaciers generally flow perpendicular to the orientation of the range and define subranges and peak groups. It is thought that many of these outlet glaciers follow the traces of large-scale geologic faults.